CN103366648B - Substrate, display screen, spliced screen and alignment method for spliced screen - Google Patents

Abstract

The invention discloses a substrate provided with alignment marks, a display screen, a splicing screen and an alignment method for the splicing screen, wherein the splicing screen includes at least two display screens with alignment marks, and the substrate of the display screen is provided with There are at least two alignment marks, and there is a height difference between different alignment marks, and the height difference is greater than or equal to the standard deviation value. The alignment marks with height differences can be formed on the back of the substrate or on the front of the substrate. In the present invention, the alignment marks are set at different heights outside the effective display area of the panel, so that there is a height difference between different alignment marks. Displaying an alignment mark and its exclusive area, even if different alignment marks are arranged together, they will not interfere with each other, so as to achieve precise positioning when the display screen is spliced, and further realize the narrow border splicing of the display screen.

Description

Alignment method of substrate, display screen, splicing screen and splicing screen

technical field

The invention relates to the field of liquid crystal display, in particular to a substrate provided with an alignment mark, a display screen, a splicing screen and an alignment method for the splicing screen.

Background technique

In recent years, the popular Compact TV (compact TV, that is, narrow-frame TV) and PID (Public Information Display, public information display) splicing display screens are used more and more widely, and the technical requirements for splicing screens and displays are also increasing. High, the splicing display screen is a large-screen splicing display screen composed of multiple display screens as display units arranged in a matrix (such as 2×2, 3×3, 4×4 and larger free unlimited splicing). The display screen displays a part of an image, and the display screens arranged in a matrix display a large image together, and can also display different images in split screens.

After all the input signals of the splicing display screen are processed by the image controller, the output is distributed to each display screen. The images displayed on each display screen can cross the boundaries of the display screens, but it is usually necessary to ensure the smallest gap between the display screens. The display quality of a single display directly affects the effect of the entire splicing screen, and different types of displays will result in very different results. The image processor is one of the core devices of the splicing display screen. Its function is to send the signals that need to be displayed, such as computer, video, network, etc., to the image splicing controller, and the processed image signals are sent to the corresponding display screens. Each display screen only displays a part of the entire image, and all the display screens add up to form a complete large picture, and the resolution of the large screen is a multiple of the resolution of each display screen. However, the image processor can only improve the video processing, and the splicing effect of the obtained splicing screen still has a very wide splicing seam, which cannot meet the needs of a narrow splicing seam. As shown in Figure 1, a 2 The splicing screen of ×2 is taken as an example for illustration, in which each display unit displays a small picture.

The narrow splicing display technology of the prior art is to compress the frame width of each existing display screen, so as to achieve the purpose of narrower seams in the middle after the splicing is completed. Figure 2 shows the alignment mark design around the narrow splicing display screen in the prior art schematic diagram. Among them, A, B, and C represent the upper left corner, lower left corner, and lower right corner of a small display screen, 1A, 2A, and 3A represent the three alignment marks in the upper left corner, and 1B, 2B, and 3B represent the three alignment marks in the lower left corner. 1 alignment mark, 1C, 2C and 3C represent the three alignment marks in the lower right corner. Any alignment mark has an exclusive area around it, which is the area where any image is prohibited, and the area of the alignment mark is 0.5mm*0.5mm, and the area of its exclusive area is 1.5mm*1.5mm. If other patterns enter the exclusive area of the alignment mark, it will cause an alarm on the production line equipment and the tape-out cannot be performed. As shown in Figure 2, there is no coverage between the three alignment marks in the upper left corner and their exclusive areas, which will not cause tape-out failure, but the three alignment marks in the lower left and lower right corners and their exclusive areas There is coverage between them, especially the coverage between the exclusive areas of alignment marks 1B, 2B and 3B in the lower left corner is very serious. The enlarged view is shown in Figure 3. The upper right corners of the exclusive area of the mark 1B and the alignment mark 2B partially overlap with the exclusive area of the alignment mark 3B, causing patterns to enter the exclusive area of the alignment mark, resulting in the failure of tape-out.

In order to realize the narrow frame of the splicing display, it is necessary to limit the margin of the existing process, reduce the width of the alignment mark of the display screen, reduce the width of the alignment mark of the substrate, and improve the accuracy and standard. However, only relying on extreme compression of the margin of the existing process does not significantly improve the narrowing of the frame of the splicing display, and the problem of affecting the display effect of the splicing display still exists.

Contents of the invention

(1) Technical problems to be solved

In view of the above-mentioned defects, at least the technical problem that the present invention can solve is how to prevent the splicing seam from being too wide during the splicing process of the splicing screen, so as to realize splicing with a narrow frame.

(2) Technical solutions

In order to solve the above problems, the present invention provides a substrate provided with alignment marks, the substrate includes at least two alignment marks, and there is a height difference between different alignment marks, and the height difference is the standard deviation value N times, N greater than or equal to 1.

Further, the standard deviation value is at least 2000 Angstroms.

Further, the alignment mark is located on the back and/or front of the substrate.

Further, the alignment marks with height difference are formed in the same film layer; or the alignment marks with height difference are formed in different film layers.

In order to solve the above problems, the present invention also provides a display screen, which includes at least a first substrate, and the first substrate is the above substrate.

In order to solve the above problems, the present invention also provides a splicing screen, which is characterized in that the splicing screen includes at least two display screens, and the display screens are the above-mentioned display screens.

In order to solve the above problems, the present invention also provides a splicing screen alignment method, characterized in that the method includes:

S1. Set alignment marks with height difference on the display screen;

S2. When splicing at least two display screens, adjust the focal length of the image observation device to align with the alignment mark of the target to perform splicing and positioning.

Further, the standard deviation value is at least 2000 Angstroms.

Further, setting the alignment marks with height difference in step S1 specifically includes:

The alignment marks with height difference are formed in the same film layer; or the alignment marks with height difference are formed in different film layers.

(3) Beneficial effects

The present invention proposes a substrate with alignment marks, a display screen, a splicing screen, and an alignment method for the splicing screen. By setting the alignment marks outside the effective display area of the display screen in a form with a height difference, it is possible to utilize The image observation equipment distinguishes the alignment marks that overlap in the exclusive area. When multiple display screens are spliced to identify the alignment, even if different alignment marks are arranged together, they will not interfere with each other. When the display screens are spliced Accurate positioning to obtain a splicing screen with narrow borders.

Description of drawings

FIG. 1 is an effect diagram of a splicing screen in the prior art;

Fig. 2 is a schematic diagram of the alignment mark design around the splicing of the narrow frame in the prior art;

Fig. 3 is a schematic diagram of the distribution of three alignment marks in the lower left corner region of the prior art;

4 is a schematic diagram of a substrate provided with an alignment mark in an embodiment of the present invention, and the alignment mark is arranged on the front surface of the substrate;

5 is a schematic diagram of a substrate provided with an alignment mark in an embodiment of the present invention, and the alignment mark is arranged on the back of the substrate;

Fig. 6 is an alignment mark Mark1 and its exclusive area in a splicing screen in an embodiment of the present invention;

Fig. 7 is an alignment mark Mark2 and its exclusive area in a splicing screen in an embodiment of the present invention;

Fig. 8 is an alignment mark Mark3 and its exclusive area in a splicing screen according to an embodiment of the present invention;

Fig. 9 is a splicing effect diagram obtained by a splicing screen in an embodiment of the present invention;

FIG. 10 is a flow chart of the steps of a splicing screen alignment method in an embodiment of the present invention.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Embodiment one

Embodiment 1 of the present invention provides a substrate provided with alignment marks, the substrate includes at least two alignment marks, and there is a height difference between different alignment marks, and the height difference is N times the standard deviation value, N is greater than or equal to 1, where the standard deviation value is the measurement accuracy of the image observation equipment used in the splicing process.

The image observation device of this embodiment may be a camera in the existing image observation device, or other image observation devices such as a microscope with higher precision than the camera, and a microscope is used as an example below. The microscope can adjust the focal length, and the focal length can be adjusted in a wide range. Alignment marks of different heights need to be observed at different focal lengths; at the same focal length, since different alignment marks have different heights, only the alignment marks corresponding to the selected focal length can be clearly seen, The alignment marks other than those corresponding to the selected focal length are blurred, so the alignment marks with height difference can be distinguished, so that the alignment marks will no longer be affected by each other.

When identifying the alignment based on the alignment mark, the image observation device uses different focal lengths to observe the alignment marks at different heights, and the focal length is adjusted accordingly according to the height of the alignment mark.

By setting the alignment marks at different heights, there is a height difference between the alignment marks. In the prior art, when the exclusive area of one alignment mark enters the exclusive area of another alignment mark, the two alignment marks cannot be distinguished, and the positioning is not accurate during splicing, resulting in a relatively large frame of the splicing screen . In the embodiment of the present invention, due to the difference in height between different alignment marks, the alignment marks overlapping in the exclusive area can be distinguished, even if the distance between the two alignment marks is very close, they can be distinguished from each other. Accurate positioning can be achieved during positioning, and good results can be obtained for processes based on alignment marks.

Preferably, the magnitude of the standard deviation values is at least 2000 Angstroms. When the standard deviation is 2000 Angstroms, two alignment marks with different heights can be distinguished. It should be noted that 2000 angstroms is the bottom line value for setting the standard deviation value, and the minimum value cannot be lower than 2000 angstroms, but it is not limited to 2000 angstroms, and it can also be a value greater than 2000 angstroms, and when the standard deviation value reaches 5000 angstroms, the effect better.

Preferably, the alignment marks are located on the back and/or front of the substrate. Forming the alignment mark on the back of the substrate does not need to consider the structure of the display area, but forming the alignment mark on the front of the substrate needs to consider other structures of the display area. The alignment marks with height difference are formed in the following two ways: the alignment marks with height difference are formed on the same film layer; or the alignment marks with height difference are formed on different film layers.

In the following, the formation of alignment marks with height difference on the same film layer on the back of the substrate and the formation of alignment marks with height difference on different film layers of the substrate will be described as examples.

Alignment marks with height difference are formed on the same film layer on the back of the substrate. Firstly, a film layer is deposited on the back of the substrate, then the photoresist is coated, the photoresist is illuminated and developed through a mask (MASK), and the desired pattern is formed on the photoresist, and then the film layer is processed. Etching, removing excess height by etching according to the preset height of each alignment mark, so as to obtain an alignment mark whose height meets the requirements. Specifically, in this embodiment, the two alignment marks in the lower left corner of FIG. Layer etching, that is, etching according to the preset height of the alignment mark, and finally the alignment marks Mark1 and Mark2 are obtained, and their corresponding numbers are 10 and 20 respectively, as shown in Figure 4, between the alignment marks Mark1 and Mark2 The height difference is twice the standard value. Preferably, the standard value is 2000 angstroms. Further, the height difference between the alignment marks Mark1 and Mark2 may be N times the standard value, where N is greater than or equal to 1.

It should be noted that the above-mentioned alignment marks may also be formed on different film layers on the back surface of the substrate. Regardless of whether the alignment mark is set on the same layer or on a different layer, when deposition and etching are performed on the back of the substrate, since the alignment mark is relatively independent from the front side, it can be set to any height difference. The size of the height difference is related to the image observation proportional to the measurement accuracy of the device. As an embodiment of the present invention, in this embodiment, the image observation equipment uses a high-precision microscope, and its measurement accuracy can reach 2000 angstroms, so the height difference between the alignment marks can be set to N times of 2000 angstroms, then Under the microscope, two alignment marks with height difference can be distinguished by adjusting different focal lengths.

Further, alignment marks are sometimes provided on the front side of the substrate according to process requirements. If it is arranged on the front side of the substrate, the patterning process of the alignment mark can be done in the existing TFT patterning process without adding additional MASK and without increasing the cost. Since the front of the substrate needs to realize the display function, the formation of alignment marks on the front of the substrate will affect the normal display of the display screen. Set registration marks. It can be formed by a patterning process, similar to the above embodiment, it can be formed by deposition, photoresist patterning process, etching and other steps. The alignment marks provided on the two different layers may be any layer forming the display region structure, and the gate insulating layer and the semiconductor active layer are taken as examples for illustration below.

Firstly, deposit the gate insulating layer on the front side of the substrate, then coat the photoresist, illuminate the photoresist through a mask (MASK), develop it, form the desired pattern on the photoresist, and then apply the gate insulating layer Etching is performed. While forming the pattern of the gate insulating layer, the pattern of the alignment mark Mark1 is obtained outside the effective display area. This is the graphic of Mark1 obtained according to the first preset height. Then, the deposition of the semiconductor active layer is carried out, and then the photoresist is coated, the photoresist is illuminated and developed through the mask plate, and the desired pattern is formed on the photoresist, and then the semiconductor active layer is etched, While forming the pattern of the semiconductor active layer, the alignment mark Mark2 is obtained outside the effective display area, which is the pattern of Mark2 obtained according to the second preset height. Thus, there is a preset height difference between the alignment marks Mark1 and Mark2. The alignment marks Mark1 and Mark2 obtained by the above process are both located on the front of the substrate, and are located on different layers of the substrate. Therefore, different layers of etching are performed on the front of the substrate to obtain alignment marks Mark1 and Mark2 with height differences, and their corresponding numbers are respectively 10 and 20, as shown in Figure 5, the height difference between the two is N times the standard deviation. Preferably, the standard deviation is 2000 Angstroms.

It should be noted that two alignment marks with height difference can also be formed on the same layer of the front surface F of the substrate by a patterning process, and the method is similar to the same-layer etching method in FIG. 4 above. According to the alignment mark etching method in Figure 4 and Figure 5, it can be seen that no matter whether the alignment mark with height difference is on the front side of the substrate or on the back side of the substrate, different alignment marks can be formed on the same layer or on different layers. layer formation.

The above FIG. 4 and FIG. 5 are illustrated by taking two alignment marks as an example, and the above method of forming alignment marks with height difference is also applicable to the formation of three or more alignment marks.

To sum up, the substrate with height difference alignment marks can separate the alignment marks with overlapping exclusive areas or very close distances, and can perform accurate positioning according to the separated alignment marks during each processing process. Identify and locate to achieve better process effects.

Based on the substrate provided with the alignment mark in the embodiment, Embodiment 1 of the present invention further provides a display screen, including at least a first substrate, and the first substrate is the above-mentioned substrate provided with the alignment mark. Taking a liquid crystal display as an example, the above-mentioned first substrate may be a color filter substrate and/or an array substrate, and alignment marks with a height difference are arranged outside the effective display area on the array substrate or the color filter substrate. The beneficial effect of setting and realizing the alignment mark is the same as the setting and realizing beneficial effect of the above-mentioned alignment mark in the substrate.

In addition to the above-mentioned substrate, the above-mentioned display screen may also include a backlight source, which is used to provide a light source for the normal display of the display screen. It should be noted that, in addition to the above-mentioned liquid crystal module composed of the substrate and the backlight, the display screen also includes other structures necessary for the display device to realize the display function, which will not be repeated here.

It should also be noted that the display screen in this embodiment is described by taking a liquid crystal display screen as an example, and it is also applicable to a display screen other than a liquid crystal display screen that realizes a display function.

Therefore, the display screen with alignment marks provided in this embodiment can distinguish the alignment marks with overlapping exclusive areas or very close distances when observed under a microscope. Accurate identification and positioning of alignment marks to achieve better process results.

Embodiment two

Embodiment 2 of the present invention provides a splicing screen comprising at least two display screens, wherein the display screens are the display screens provided in Embodiment 1 above.

In this implementation, there are three alignment marks Mark1, Mark2 and Mark3 that need to be used in different process flows, where Mark1 is the mark used for cutting in the cell process, and Mark2 is the mark used in the module process POL ( Polarizer bonding) process and OLB (binding) process are used for alignment, Mark3 is the mark used for UV (ultraviolet curing) process black matrix (BM) alignment, these three alignment marks have In the respective exclusive areas, images are prohibited to appear in the exclusive areas. If the exclusive areas overlap with the exclusive areas of other alignment marks, the positioning will be inaccurate.

Taking the liquid crystal panel as an example, the above-mentioned three alignment marks Mark1, Mark2 and Mark3 are arranged outside the effective display area W of the liquid crystal panel, and are arranged on the liquid crystal panel in increasing or decreasing order.

When splicing multiple display screens, the image observation equipment that needs to be used for positioning is generally a camera or a microscope. The height difference between the positioning marks is greater than or equal to the standard deviation value. When the standard deviation value is 2000 Angstroms, the two Alignment marks of different heights are distinguished. It should be noted that 2000 angstroms is the bottom line value for setting the standard deviation value, and the minimum value cannot be lower than 2000 angstroms, but it is not limited to 2000 angstroms, and it can also be a value greater than 2000 angstroms. When the standard deviation value reaches 5000 angstroms, the effect is better good.

Figure 6 is the alignment mark and its exclusion area observed when the focal length corresponding to the alignment mark Mark1 is selected for observation during the box forming process, and Figure 7 is the selection and alignment mark Mark2 during the POL&OLB process The alignment mark and its exclusive area observed when the corresponding focal length is observed. Figure 8 shows the alignment mark and its exclusion area observed when the focal length corresponding to the alignment mark Mark3 is selected for observation during the UV process. it area.

By using the alignment marks with height difference provided by this embodiment to splicing the display screen, when the exclusive areas of different alignment marks overlap each other, the image observation device can only see the alignment by using the selected focal length to identify the alignment. The alignment mark corresponding to the selected focal length and the exclusive area of the alignment mark can be seen, but the other alignment marks and the exclusive area of the other alignment marks cannot be seen. Therefore, even if the exclusive areas of the alignment marks partially overlap, the recognition and alignment will not be affected. The effect of the splicing screen obtained by using the above splicing process is shown in Figure 9. Compared with the effect diagram of the prior art splicing screen in Figure 1, the splicing seam is obviously narrowed, and for large-size (46' or more) splicing screens In other words, the splicing seam of the original splicing screen is 7-10mm, and the splicing of the obtained splicing screen can be reduced to 4-6mm by using the substrate with the height difference alignment mark provided by this embodiment for splicing.

In the narrow-frame splicing screen provided by this embodiment, the alignment mark outside the effective display area of the panel is made into a form with a height difference on the substrate. When performing identification and alignment, only the focal length of the image observation device needs to be adjusted. Only one alignment mark and other areas can be seen under the focal length, even if different alignment marks are arranged together, they will not interfere with each other, so that different alignment marks can be set at relatively close positions to achieve a narrow frame stitching.

To sum up, the narrow-frame splicing screen provided by this embodiment sets the alignment marks to different heights outside the effective display area of the panel, so that there is a height difference between different alignment marks. When performing identification and alignment, the image When the observation equipment sets a focal length, only one alignment mark and its exclusive area can be displayed in the image. Even if different alignment marks are arranged together, they will not interfere with each other, so as to perform accurate alignment and realize the display screen narrow border stitching.

Embodiment three

Embodiment 3 provides a method for realizing a splicing screen with a narrow border, and the step flow is shown in FIG. 10 , which specifically includes the following steps:

Step S1, setting alignment marks with height differences on the display screen.

Further, the height difference is N times the standard deviation value, and N is greater than or equal to 1. Preferably, the standard deviation value is the measurement accuracy of the image observation equipment used in the stitching process.

Taking a liquid crystal display as an example, the display screen includes: a backlight and a liquid crystal panel. The liquid crystal panel is a liquid crystal panel based on alignment marks. Between the liquid crystals, the alignment marks are arranged outside the effective display area on the array substrate or the color filter substrate, and the color filter substrate and/or the array substrate are substrates on which the alignment marks have a height difference. Of course, the display screen may also be a display screen other than a liquid crystal display screen that realizes a display function.

Wherein in step S1, setting the alignment mark with height difference specifically includes:

Alignment marks with height difference are formed by etching in the same layer; or alignment marks with height difference are formed by etching in different layers separately. This has been described in detail in Embodiment 1, and will not be repeated here.

Step S2 , when splicing at least two display screens, adjust the focal length of the image observation device to align with the alignment mark of the target.

By adjusting the focal length of the image observation device, only one alignment mark and its exclusive area can be displayed in the image by setting a focal length, and the alignment marks with height differences can be distinguished for precise alignment , to perform splicing and positioning to obtain a narrow-frame splicing screen.

When identifying alignment, alignment marks of different heights correspond to different focal lengths of image observation equipment. When performing different processing techniques, it is necessary to select the corresponding focal length for observation according to the alignment marks required by the process. For example, in the box forming process, it is necessary to perform positioning according to the alignment mark of Mark1, and the focal length of the image observation equipment needs to be adjusted to the focal length corresponding to the height of Mark1; in the POL&OLB process, it is necessary to perform positioning according to the alignment mark of Mark2 , it is necessary to adjust the focal length of the image observation equipment to the focal length corresponding to the height of Mark2. In the UV process, it is necessary to position according to the alignment mark of Mark3, and it is necessary to adjust the focal length of the image observation equipment to the height of Mark3. corresponding focal length.

When performing a certain process, the image observation equipment selects the focal length corresponding to the alignment mark required by the process. Under this focal length, only the alignment mark can be observed, but other alignment marks cannot be seen, so Easily distinguish the different alignment marks. Because any image is prohibited in the exclusive area of the alignment mark, only the required alignment mark can be seen when a certain process is performed, while other alignment marks are not in the display area, so as to avoid mutual influence. Taking the box forming process, POL&OLB process and UV process as examples to illustrate, the results of the alignment mark and its exclusion area observed in the three process processes are the same as those shown in Figure 6-8 above. Even if different alignment marks are arranged together, they will not interfere with each other, so that different alignment marks can be set at relatively close positions to achieve narrow frame splicing, making the splicing seam narrower, for large sizes (46 'Above) the splicing screen, from the original 7 ~ 10mm can be reduced to 4 ~ 6mm.

Preferably, the magnitude of the standard deviation values is at least 2000 Angstroms. When the standard deviation is 2000 Angstroms, two alignment marks with different heights can be distinguished. It should be noted that 2000 angstroms is the bottom line value for setting the standard deviation value, and the minimum value cannot be lower than 2000 angstroms, but it is not limited to 2000 angstroms, and it can also be a value greater than 2000 angstroms, and when the standard deviation value reaches 5000 angstroms, the effect better.

By using the narrow frame splicing screen splicing method provided by this embodiment, it is not necessary to change the position of the overlapping alignment marks in the existing process, but to make the alignment marks outside the effective display area of the panel different heights, so that different alignment marks There is an obvious height difference between the alignment marks. When identifying the alignment, you only need to adjust the focal length of the display device. At the same focal length, only one alignment mark and other areas can be seen, even if different alignment marks are arranged on the Together, they will not interfere with each other, so that different alignment marks can be set at close distances to achieve narrow border splicing.

The above embodiments are only used to illustrate the present invention, but not to limit the present invention. Those of ordinary skill in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all Equivalent technical solutions also belong to the category of the present invention, and the scope of patent protection of the present invention should be defined by the claims.

Claims (9)

1. A substrate provided with alignment marks, characterized in that the substrate includes at least two alignment marks, and there is a height difference between different alignment marks, and the height difference is N times the standard deviation value, N is greater than or equal to 1; The standard deviation value is the measurement accuracy of the image observation equipment used in the stitching process. 2. The substrate of claim 1, wherein the standard deviation value is at least 2000 Angstroms. 3. The substrate according to claim 1, wherein the alignment mark is located on the back and/or front of the substrate. 4 . The substrate according to claim 1 , wherein the alignment marks with height difference are formed by the same film layer; or the alignment marks with height difference are formed by different film layers. 5. A display screen, comprising at least a first substrate, wherein the first substrate is the substrate according to any one of claims 1-4. 6. A splicing screen, characterized in that the splicing screen comprises at least two display screens, and the display screens are the display screens described in claim 5. 7. A method for alignment of a splicing screen, characterized in that the method comprises: S1. Set alignment marks with height difference on the display screen; S2. When splicing at least two display screens, adjust the focal length of the image observation device to align with the alignment mark of the target to perform splicing and positioning. 8. The method of claim 7, wherein the standard deviation value is at least 2000 Angstroms. 9. The method according to claim 7, wherein the step S1 setting the alignment mark with a height difference specifically comprises: The alignment marks with height difference are formed in the same film layer; or the alignment marks with height difference are formed in different film layers.